Carbon dioxide gas absorbent and carbon dioxide gas separating apparatus

• US 6,712,879 B2
• Filed: 09/06/2002
• Issued: 03/30/2004
• Est. Priority Date: 09/28/2001
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Essaki, Kenji, Nakagawa, Kazuaki, Kato, Masahiro, Yoshikawa, Sawako
• Primary Examiner(s): Spitzer, Robert H.
• Application Number:
  US10/235,663
• Publication Number:
  US 20030075050A1
• Time in Patent Office: 571 Days
• Field of Search: 951/39, 961/08, 961/21, 961/46, 961/53, 961/43, 423/230, 502/400
• US Class Current: 95/139
• CPC Class Codes: B01D 2253/10 Inorganic adsorbents
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/106 Silica or silicates
• CPC Class Codes: B01D 2253/304 Linear dimensions, e.g. particle shape, diameter
• CPC Class Codes: B01D 2253/311 Porosity, e.g. pore volume
• CPC Class Codes: B01D 2256/22 Carbon dioxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2259/40086 by using a purge gas B01D2259/4009 takes precedence
• CPC Class Codes: B01D 2259/402 using two beds
• CPC Class Codes: B01D 53/0407 Constructional details of adsorbing systems
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

There is disclosed a carbon dioxide gas absorbent comprising lithium silicate, 0.5 mol % to 4.9 mol % of alkali carbonate per mole of the lithium silicate, and at least one element selected from the group consisting of aluminum, magnesium, calcium, iron, titanium and carbon.

Claims

1. A carbon dioxide gas absorbent comprising:

lithium silicate;

0.5 mol% to 4.9 mol% of alkali carbonate per mole of said lithium silicate; and

at least one element selected from the group consisting of aluminum, magnesium, calcium, iron, titanium and carbon.

2. The carbon dioxide gas absorbent according to claim 1, wherein the content of said alkali carbonate is in the range of 1 mol% to 3 mol% per mole of said lithium silicate.

3. The carbon dioxide gas absorbent according to claim 1, wherein said lithium silicate comprises at least one compound selected from the group consisting of Li₄SiO₄, Li₂SiO₃, Li₆Si₂O₇ and Li₈SiO₆.

4. The carbon dioxide gas absorbent according to claim 1, wherein said lithium silicate comprises Li₄SiO₄.

5. The carbon dioxide gas absorbent according to claim 1, wherein said alkali carbonate comprises at least one compound selected from the group consisting of potassium carbonate, sodium carbonate and lithium carbonate.

6. The carbon dioxide gas absorbent according to claim 5, wherein said alkali carbonate comprises potassium carbonate.

7. The carbon dioxide gas absorbent according to claim 1, which substantially assumes a powdery form.

8. The carbon dioxide gas absorbent according to claim 7, wherein said powdery form has an average particle diameter ranging from 0.5 μ

m to 50μ

m.

9. The carbon dioxide gas absorbent according to claim 1, which substantially assumes a porous form.

10. The carbon dioxide gas absorbent according to claim 9, wherein said porous form has a porosity ranging from 30% to 60%.

11. A carbon dioxide gas separating apparatus comprising:

a reaction chamber having a carbon dioxide gas inlet and a product gas outlet;

a carbon dioxide gas absorbent placed in said reaction chamber;

said carbon dioxide gas absorbent comprising lithium silicate;

0.5 mol% to 4.9 mol% of alkali carbonate per mole of said lithium silicate; and

at least one element selected from the group consisting of aluminum, magnesium, calcium, iron, titanium and carbon; and

a heater heating said reaction chamber and disposed around said reaction chamber.

12. The carbon dioxide gas separating apparatus according to claim 11, wherein the content of said alkali carbonate is in the range of 1 mol% to 3 mol% per mole of said lithium silicate.

13. The carbon dioxide gas separating apparatus according to claim 11, wherein said lithium silicate comprises at least one compound selected from the group consisting of Li₄SiO₄, Li₂SiO₃, Li₆Si₂O₇and Li₈SiO₆.

14. The carbon dioxide gas separating apparatus according to claim 11, wherein said lithium silicate comprises Li₄SiO₄.

15. The carbon dioxide gas separating apparatus according to claim 11, wherein said alkali carbonate comprises at least one compound selected from the group consisting of potassium carbonate, sodium carbonate and lithium carbonate.

16. The carbon dioxide gas separating apparatus according to claim 15, wherein said alkali carbonate comprises potassium carbonate.

17. The carbon dioxide gas separating apparatus according to claim 11, wherein said carbon dioxide gas absorbent substantially assumes a powdery form.

18. The carbon dioxide gas separating apparatus according to claim 17, wherein said powdery form has an average particle diameter ranging from 0.5 μ

m to 50 μ

m.

19. The carbon dioxide gas separating apparatus according to claim 11, wherein said carbon dioxide gas absorbent substantially assumes a porous form.

20. The carbon dioxide gas separating apparatus according to claim 19, wherein said porous form has a porosity ranging from 30% to 60%.